Express this product in scientific notation: $(7.00\times 10^{-1})\times (9.00\times 10^{-2})$
Solution: Start by collecting like terms together. $= (7.00\times 9.00) \times (10^{-1}\times 10^{-2})$ When multiplying exponents with the same base, add the powers together. $= 63.0 \times 10^{-1\,+\,-2}$ $= 63.0 \times 10^{-3}$ To write the answer correctly in scientific notation, the first number needs to be between $1$ and $10$ . In this case, we need to move the decimal one position to the left without changing the value of our answer. $ $ We can use the fact that $63.0$ is the same as $6.300 \times 10$ $ = {6.300 \times 10} \times 10^{-3} $ $= 6.300\times 10^{-2}$